I'm no mechanic but I've been doing a lot of used table shopping, and can give my opinion. That's an AMF grand prix, and for $450 you're not likely to find a better quality table at that price range too often considering the quality of that is equal to a gold crown.
It could be georgous if you wanted to strip and sand it and stain and polish everything, but that's a lot of work. It is hardwood under that paint though, and the castings can be sanded and polished up if they're scratched or ugly but that's all time consuming and a lot of work. Slates can be fixed if they're half decent, I think those are pinned like a gc so be careful, take it apart the right way assuming they are pinned.
If that's the best deal you can find and you like the looks I'd probably buy it even if it needed some work. But it's up to you, there are plenty of good deals around if you keep your eye's open and wait patiently for them. I just bought my beater gold crown 1 cheap and spent the last month fixing it, then this pops up:
http://portland.craigslist.org/clk/spo/2560591410.html
hmmm Doesn't get better than that for $200...
I don't know what model that is but it looks like a brunswick frame and it's driving distance from me, I'm sure tempted...
Any of these quality tables can be refinished repaired and polished up and made to look like new, given enough work and patience and money for new cloth and pockets and whatever else you need to do the job. If it needs rubber and simonis and new pockets and a mechanic too then you're going to be in the over $1000 range easily, not counting your time refinishing it so might not end up being the best deal in town. You can use the above to bargain the price down if it needs more than the seller realized. You can always leave an offer for less and tell them to call you if they can't get their asking price.